Fraunhofer-Institut für Produktionsanlagen und Konstruktionstechnik IPK

Filters
Reset filters

Settings
Now showing 1 - 8 of 8
  • Publication
    PowerGrasp: Concept for a novel Soft-Robotic Arm Support System
    ( 2018)
    Kuschan, Jan
    ;
    Goppold, Jean-Paul
    ;
    Schmidt, Henning
    ;
    Krüger, Jörg
    This paper presents a novel concept and first modules for a soft-robotic arm support system for application in overhead assembly in automotive industry. Repetitive manual tasks and associated body movements are still typical in industrial assembly jobs. Even without an additional load or tool, such tasks are monotonous and often lead to stress in the musculoskeletal system, which frequently causes pain and injuries. In light of ageing industrial workforce, solving this problem becomes a major challenge for ergonomics researchers and engineers. In this paper we present a novel active soft orthotic device which is not an exoskeleton, even though there are some similarities. It is designed to induce only moderate external forces into the human skeleton for muscle fatigue compensation, without causing harm. The concept involves different soft-robotic actuators, depending on the human arm joints to be supported, as well as concepts for control, energy storage and sensors. By detecting muscle fatigue of the worker we created an active assist-as-needed system, which has advantages in energy consumption on the one hand and prevents muscle atrophy of the worker on the other hand. To fulfill these requirements we developed pneumatic actuators, which adjust themselves to the user without external calibration. This automatic calibration process requires no special knowledge of the employees and takes place only by using separated pneumatic chambers and adjustable straps and buckles. By using strain gauges and inertial measurement units, as well as pressure sensors and force sensors we measure and analyze all necessary information for the position related force control in real time. We also present first evaluation results with static overhead retaining tasks.
  • Publication
    Cooperation of human and machines in assembly lines
    ( 2009)
    Krüger, Jörg
    ;
    Lien, Terje K.
    ;
    Verl, Alexander
    Flexibility and changeability of assembly processes require a close cooperation between the worker and the automated assembly system. The interaction between human and robots improves the efficiency of individual complex assembly processes, particularly when a robot serves as an intelligent assistant. The paper gives a survey about forms of human-machine cooperation in assembly and available technologies that support the cooperation. Organizational and economic aspects of cooperative assembly including efficient component supply and logistics are also discussed.
  • Publication
    A process model for elastomer-metal-pressfits
    ( 1995)
    Neu, S.
    ;
    Seliger, G.
    This paper descibes an analytical and numerical process model for elastomer-metal-pressfits. Based on the mathematical description of the fitting process, methods and experiments to identify the values of the process parameters, is checked by statistical comparison. In addition to analytical process formulation, numerical methods like Boundary Element Methods are used. Sliding friction values of a number of elastomer-metal-pressfits are examined experimentally. The results of the examination of ail parameters and the applicability of the model are discussed by an elastomer-metal absorbing spring.
  • Publication
    Analysis of the geometrical features detectability constraints for laser-scanner sensor planning
    ( 1994)
    Seliger, G.
    ;
    Zussmann, E.
    ;
    Schuler, H.
    This paper presents a planning approach or automatically synthesis of the viewpoint locations of a laser scanner that satisfy the detectability constaints of the geometrical feature of a given object. Dominant constraints taken into consideration were: the laser scanner field of view, depth of view, and the maximum permissible view angle. The approach is task driven and sensor model based. Information is given about the scanned object and its selected features, as well as about the optical characteristics of the sensor. Planning is presented as an optimization problem where the optimal laser scanner viewpoint must satisfy all the constraints simultaneously. The approach is demonstrated by scanning a 2D feature, and through planning an experiment in which robotic assembly of a car door is assisted by a laser scanner.
  • Publication
    Knowledge-based integration of design and assembly process planning
    ( 1993)
    Seliger, G.
    ;
    Hsieh, L.-H.
    ;
    Wang, Y.
    Concurrent engineering is an approach for fast product development. To support concurrent product design and process planning effective tools are needed. This paper desribes the development of a knowledge-based system for this approach. lt consists of tools for feature-based product design, design for assembly analysis, and process planning. All tools work on an integrated product and process model. The integrated model and the data structure of the developed assembly-features are discussed. The perspective of using knowledge-based methods for realizing concurent engineering is described.
  • Publication
    Rechnerunterstützte Bereitstellung von Montageprozeßwissen für die Konstruktion
    ( 1992)
    Krüger, S.
    ;
    Neu, S.
    The paper presents a software tool that supports design for assembly in an early design stage. It integrates a 3D solid modeller, an expert system shell and an object-oriented data base, thus providing parallel knowledge-based support in DFA through a CAD-system. At first, the paper describes an integrated information model which serves as a basis for the system development. It is structured into data models for product, process, assembly equipment and order, which has been described using the STEP-EXPRESS language. The data models have been implemented in the expert system object base. Assembly process knowledge is represented within the knowledge base in form of frames, constraints and IF-THEN-rules. Subsequent to the description of the system's architecture four application examples which are concerned with the assembly of mobile telephones are presented. These examples are optimizing of drilling hole coordinates for automated assembly of printed circuit board and telephone housing, optimizing the groove profile for automated pressing-in of a flexible gasket, the selection of standardized endeffectors and the precalculation of assembly costs.
  • Publication
    3D-CAD-Bausteine für die Simulation von Bearbeitungsabläufen
    ( 1990)
    Germer, H.-J.
    ;
    Rieger, R.
    ;
    Trebo, D.
    ;
    Krause, F.-L.
    The current situation of CAD/CAM-systems is marked by a lack of software modules which provide and process the computerinternal models in a task-oriented manner. In connection with company-wide usable data bases, geometry-processing user modules can be decisive support for the production areas following design. 3D-CAD-based simulation systems take on an important role for the planning and manufacturing of products. In this paper, 3D-CAD-modules for the configuration of manufacturing environments as well as for the simulation of manufacturing processes are introduced.
  • Publication
    Integrated planning and off-line programming system for robotized work cells.
    ( 1989)
    Bernhardt, R.
    The paper gives a short survey of the ESPRIT 623 project: Operational Control for Robot System Integration into CIM, Systems Planning, Implicit and Explicit Programming in which twelve companies, universities and research institutions are involved. About three years after the project's commence work has started to combine software modules developed by different partners to integrated systems with increased functionality. To accomplish this four working groups have been installed which are working on different aspects, e.g. access to different data bases or direct usage for industrial application. These realized system reflect also the specific interests of the involved companies. In this paper the realized inegrated planning and explicit offline programming system is presented in more detail and some applications reaching from off-shore over the automotive industry up to space technology are described.